Control for lamp bank displays



ATrYs.

R. N. SHERWIN Jan. 19, 1965 CONTROL FOR LAMP BANK DISPLAYS Filed March 22, 1963 Jan, 19, 1965 R. N. sHERwlN -coNTRoL Foa LAMP BANK DISPLAYS 9 Sheets-Sheet 2 Filed March 22, 1963 mm R w. f v @Ssn m m WE .z o. m M f VS w 5 N. ,5, v EIE M E. m @w l .m m E m. .pm T 5223 QM QQNQ QFOIL ...IQ l 2Q mit. k Qho mh 0 ...12ms oh @Nia mbv@ ATTYS.

Jan. 19, 1965 s vR. N. sHERwIN 3,165,742

CONTROL FoR LAI/IP BANK DISPLAYS Filed March 22, 196s 9 sheets-sheet 5 v INVENTOR. w RICHARD N. SHERwIN ATP/.5.

Jan. 19, 1965 R. N. sHERwlN CONTROL FOR LAMP BANK DISPLAYS 9 Sheets-Sheet 4 Filed March 22, 1963 A TTY s.

Jan. 19, 1965 R. N. sHERwlN CONTROL FOR LAMP BANK DISPLAYS 9 Sheets-Sheet 5 Filed March 22, 1963 w L n" N 19:30 wzmh moQm 3.582 55S# .30E fll Q .mnt S INVENTOR.

Arms.

Jan- 19, 1965 R. N. sHERwlN 3,166,742

CONTROL FR LAMP BANK DISPLAYS Filed March 22, 1965 9 Sheets-Sheet 6 INVENTOR. RICHARD N. HfRw/N Jan. 19, 1965 R. N. sHl-:RwlN 3,165,742

CONTROL FOR LAMP BANK /l/ISPLAYS Filed March 22, 1963 9 sheets-sheet 7 IIZ H3 INVENTOR. RICHARD N. .SHERw/N Jan. 19, 1965 R. N. sHERwlN 3,166,742

CONTROL FOR LAMP BANK DISPLAYS Filed MaI'Ch 22, 1963 9 Sheets-Sheet 8 I NV ENTOR. RICHARD N. SHERw/N BY//Jlz Arm.

Jan. 19, 1965 R. N. sHERwlN 3,165,742

CONTROL FOR LAMP BANK DISPLAYS Filed March 22, 1963 9 Sheets-Sheet 9 isf 1I//o l j/o Q Q| *I u @lL-@ `D f Si s a V s@ xk K M s v m s s 1 I e ll en@ r 2li 1:

INVENTOR. RICHARD N. HERw/N ATTYS.

United States Patent 3,166,742 CGNTEGL FR LAMP BANK DISELAYS Richard N. Sherwin, Rockt'ord Iiay, Idaho, assigner to American Sign it Indicator Corporation, Spokane, Wash., a corporation of Washington Filed Mar. 22, i963, Ser. No. 267,292 7 Claims. (Cl. 34th-33d) using semi-conductor components for high eiiiciency andv low maintenance. The present application utilizes transistors, diodes and silicon controlled rectifiers (SCR). These modern electronic components allow one to better utilize FIGURE l is a front view of a second lamp bank which might be utilized with regard to the present controls;

FIGURE 11 is a sectional view cut along line 11-11 in FIGURE FIGURE 12 is an enlarged View of the upper left hand corner as seen in FIGURE l1; and

FIGURE 13 is a schematic wiring diagram of a second embodiment of the invention.

Geneml description Referring now to the drawings, and particularly to the over all schematic view shown in FIGURE l, this invention is illustrated as it might be applied to a lamp bank display for alternately displaying time and temperature.

, The lamp bank comprises three basic groups of lamps inprinted circuitry and modular units, andinsure a long ments themselves lare not subjected to the operating cur rents required in the lamp bank, but operate instead in a low power circuit, thus reducing the over all costs and heat losses in the rnecl'ianisrn.v As a further object, the control provides automatic brightness control for the lamps by monitoring of the controlling elements in the selective circuit which produces the desired figures on the bank.

Another object of this invention is to provide a novel lamp bank control which is applicable to any common type of lamp bank, whether the figures displayed are changeable or constant.

n These and further objects will be evident from a study of the attached drawings and the description below. While this disclosure shows two alternate forms of circuitry that might be utilized in the control of a lamp bank, it is to be emphasized that the particular cornponents shown in the diagram and described below are merely exemplary and are not intended to restrict the scope of this invention to a particular application. The extent of this invention is clearly set out in the claims following this description.

In the drawings:

FIGURE 1 is a schematic block diagram of the circuitry utilized according to this invention in a device for displaying time and 4temperature alternatelyy upon a lamp bank; v

FIGURE 2 is a schematic wiring diagram of the power` controls for the circuitry shown in FIGURE 1;

FIGURE 3 is a schematic wiring diagram of the ring counters utilized in the control system shown in FIGURE 1;

FIGURE 4 is a. schematic wiring diagram of the diode matrices and lamp controls shown in FIGURE 1;

FIGURE 5 is a schematic view of the temperature sensing devices and switching mechanisms shown in FIGURE l;

FIGURE 6 is a back view of a temperature sensing mechanism which might be utilized in the controls of FIGURE 1;

FIGURE 7 is a front view of the device shown in FIG- URE 6; Y

FIGURE 8 is -a top view of the device seen in FIGURE 6;

FIGURE 9 is a bottom view of the device shown in FIGURE 6;

dicated generally as It), 11 and l2. These lamp banks are not shown in detail but might utilize the same arrangement as shown in Patent No. 3,041,596, granted to Edward M. Caierro et al., on .une 26, 1962, for display signs. Each of the lamp banks 10, 11 and 12 includes several subgroups of lamps which are selected so as to display the desired numeral. The lamp bank I0 is utilized in the display of hours andin the display of the tens in a temperature unit. The lamp bank Il is used to display the ten-minute digits in the time display and also to show the units in a temperature display. The right-hand bankl 12 is used to display the unit minutes in a time display and also to show a degree sign in a temperature display. In addition, the lamp bank Iii includes a group of lamps used to show a minus sign during certain temperature displays and two lamps are normally included between the banks I@ and Il to show the necessary colon in the time displays. The physical arrangement of the lamps in banks Iii, 1l and l2 is unchanged from that disclosed in the prior patent above and will not be further described herein.

The lamp banks are operated from a'source of pulsating direct current power i3 which may be a source of unltered rectiiied alternating current. The source of D.C. power 13 is connected to the lamp banks 10, 11 and 12 through a series of SCR switching circuits, generally designated as Id, 15 and i6. The SCR in each of the circuits M, I5 and I6 controls the individual lamp groups of each of the lamp banks l0, 11 and l2 respectively. Thus, when the individual SCRs are activated, there will be completed a circuit to the lamps of the respective groups so as to activate these lamps and produce a lighted display on the banks 10, 11 and 12.

The SCR switching circuits 14, 15 and 16 are controlled respectively by three diode matrix modules 17, 18 and 19 respectively. Each of these modules has a blocking connection of diodes to produce individual circuits capable of showing the desired digits in the displays to be produced on the lamp banks 10, 11 and 12. Each matrixv module 17, 18 and I9 has two or more inputs.

The diode matrix modules 17, 18 and 19 in the example shown are alternately controlled Vby a temperature servo mechanism 2u and a ring counter circuit comprising an hours counter 2i, a ten-minute counter 22 and a minute counter 23. The minute counter 23 is monitored by a timing signal generated in a circuit 24 and the ring counter 23 in turn operates the counter 22 which, in turn, controls the counter 2l. The temperature servo mechanism 20 is operated by a temperature sensor 25 through an amplifier 26.

The alternating display is controlled by a continuously operable timer 27 and an Valternating switch 28 operated thereby. The phase of the SCRs in circuits 14, 15 and 16 is controlled by a signal generator 29 which is under the control of a photo-conductive cell 30 that monitors existing light conditions at the lamp banks 10, 11 and 12.

.of alternating current power.

arsenain general, then, the lamp banks il?, lll and l2 are operated by SCR switching circuits llfi, l5 and lo which select the lamps to be lighted by the source of power i3. n the first embodiment illustrated, the SCR circuits ld, l5 and le are controlled by diode matrixes l, liti and i9, there being an individual input into each diode matrix l and l@ for each numeral to be displayed on the banks controlled thereby. These individual inputs of the niatrixes i118 and l@ are in turn selected by the ring counters El, 22 and lor by the temperature servo mechanism Ztl. The alternating displays are selected by a time f switch 28 from the signalgenerator 29 which produces the Power conlrols The signal generator 29, switch 28 and the various controls for the electronic clock mechanism are illustrated in i greater detail in FlGURE 2. At the top ot this figure are shown two inputs 3l, 32 connected to a suitable source Located in series with the input 3l is a master switch 33 which controls the entire mechanism. The inputs 3l. and ft2 are connected to a rectitying transformer 3d which converts the alternating current power to a low-voltage, pulsating direct current in lines and The line 35 includes an SCR 37 wired in series with the previously described switch 23 which is controlled by the timing motor 27. The line Elo comprises the gate signal ground for the SCR in each of the circuits 14, l5 and lo. The line 35 is selectively connected by switch 213 to lines 3S and 39 which comprise the gate power lines to the temperature controls and time controls respectively. The SCR 37 acts as an amplilier in the main circuit for the lamps, controlling the power to tie time and temperature-indicating mechanisms as deterinthe lamps for night use, while the resistance ft2 may be manually adjusted to set the upper limit of brightness in the lamps for daytime use. The photo-conductive cell Pill varies the phase angle of the oscillator di?, which in turn triggers the gate ot SCR 37, thereby producing a variable pulsating voltage at the alternating switch 23.

. By reducing the period of the pulse in the current flowing through switch Z8, the signal generator 29 therefore con trols the brightness of the lamps lighted in the lamp banks llt?, lil and l2.

Clock mechanism The lower portion of FIGURE 2 shows the power supply for the ringy counters 2l, Z2 and 23. The DC. power supply lo is filtered at l5 and is connected to a voltage regulator d6. The output or the voltage regulator to is supplied through lines i7 and 48. Line includes a rese switch el?. The line comprises the positive power supply to the ring vcounters 2l, Z2 and 23, while the line 47 is the common ground to these ring counters 2l, and 23. ln order to insure continuous counting operation of the clock mechanism during a temporary power failure, there is provided a standby batterysupply Sii which is connected by means or a blocking diode 5l to the output connections or the power supply The blocking diode 5l insures that current during normal operation will not flow from theypower Asupply @i4 to the battery supply The timing signal device-24tcomprises a one-minute timing motor 52 which operates an alternating switch The switch i3 produces a pulse at a line Sil by alternately charging and discharging ay condenser 55 through SCR and resistor 57. The pulse is transmitted through a switch 5S to theline 5? to drive the minute ring counter 23.

ln order to allow manual setting ot the clock mechanism, there is provided a condenser oil that is charged by the battery 5@ when the reset switch il@ has been opened. The condenser et? is manually discharged through a resistor 6l by closing or simultaneously-operated switches 6L?, and 63 to reset the hours ring counter 2l. The switch d2 closes the circuit across resistance 6l while the switch o3 connects the resistance 6l to a line 6d which transmits the pulse to the ring counter El. Each time the switches 62 and o3 are manually closed, a single pulse will be transmitted to the ring counter 2l to thereby set the hours counter 2l alone. A pair of similar switches d5 and ou are utilized to manually set the lO-minute ring counter A switch 65 serves to* discharge condense' @il through the resistance 6l while switch ed connects the resistance dll to line o7 wired to the ring counter 22.V

Flhus, each time the switches 65 and 66 are manually closed, `the ring counter 22 will receive one pulse through the line 67. The minutes ring counter 23 is controlled through switches and 5S in the same manner, the switch serving to discharge condenser o@ through the resistance di and the switch SS serving to transmit the pulse through line to the ring counter Z3.

The line transmits the normal pulse each minute from line through an amplifier 69 to the three ring counters 2l, 22 and Z3 shown schematically in Fl@- 3. The am;A er till feeds the pulse to a series of ill-p-ilop circuits generally designated by the numerals "/tl. Each circuit 7@ is a transistor circuit having aninput connection fil through which the pulse is delivered and an output at TZ connected-to a gate transistor 73. The circuits 70 are connected at 'lot in such a fashion that each pulse through the line 5@ will cause a successive circuit 7@ to conduct at As each circuit 7o is turned.

off bythe succeeding pulse through line S9, the next circuit 7b-will be .turned on dueto the connection at 7M. 'lfhe inal circuit lill inthe ring counter 2.3 is connected back final output or the last llip-op circuit 7) in ring counter Y 23 is wired through an amplifier 75 to the input of a similar flip-hop circuit i6 in the ten-minute ring counter 22. Each circuit in also includes a pulse-receiving input 77 and anoutput 78 connected to a gate transistor 79. Each circuit 76 is also connected to its succeeding circuit by a connection designated as Sil. The iinal circuit "i6 is wired back to the initial circuit 76 by a connecting line di. ln a time system, the ten-minute ring counter 22 will include six circuits '76, which will be activated successively by the pulse transmitted through amplifier i5 from the tina] circuit 7'@ of the ring counterZi. The six circuits 76 are utilized to select the six numerals, 0 through 5.

The ring counter 2l, used to designate hours, comprises a series of flip-flop transistor circuits labelledgener'ally as 82. Ring counter 2l is connected to the, nal circuit 'lo of ring counter 2.2 through an amplifier $53. Each circuit SZ has an input ltwhich receives the pulse transmitted through amplifier S3 from the iinal circuit 76 of ring counter 22. Each circuit 32 also has an output at connected 'to a gate transistor do. The successive cir-` cuits SZ are connected by lines 8?, so that a pulse through` the amplier 33 will successively cause the circuits S2 to conduct. The final circuit $52 is also connected to the initial circuit 82 by means ot line Again the number of circuits d2 is determined by the number or digits to be displayed. in the case of a normal IZ-hour clock mechain the ring counter 21 so as to successively energize the numerals l through 24.

The gate transistors 73, 79 and 86 are wired to the positive power line 4S from the power supply 44 and to the gate power supply 39 from the signal generator 29. The gate signals from the transistors 73, 79 and 86 are transmitted through lines 89, 9i) and 91, respectively. Thus, from the minutes ring counter 23 there are ten gate signal outputs 89. The ten-minute ring counter 22 has six gate signal outputs 90, and the ring counter 21 for hours has twelve gate signal outputs 91. As each pulse is received through the line 59, there will be a pulse generated through one of the gate signal outputs 89. There will also be a pulse generated through one of the gate signal outputs 90 and 91. However, the activated gate signal output of the ring counters 22 and 21 will change only every l0 pulses and 60 pulses, respectively. Thus, the signal through the outputs S9 will be an indication of minutes while the signal through the outputs 99 will be an indication of ten-minute intervals, and the signal through the outputs 91 will be an indication of hour intervals.

In addition to the successive activation of the ring counters 21, 22 and 23, there are also included inputs 59, 67 and 64 by which the individual ring counters 23, 22 and 21, respectively, may be manually reset as described above. It will be seen that resetting the minutes ring counter 23 will automatically cause the ten-minutes ring counter 22 and the hours counter 21 to be reset in succession, while the resetting of the ten-ninutes ring counter 22 will also control the hours ring counter 21.

Lamp controls The diode matrix modules 17, 1S and 19 are illust-rated in FIGURE 4. The minutes diode matrix 19 has a series of inputs 92 which are respectively connected to the individual Vgate signal outputs 89 shown in FIGURE 3. Each of the inputs 92 is connected by means of a diode 93 and an individual circuit-blocking diode 94 to a limiting resistor 95 wired to the gate of a power SCR 96. Each SCR 96 is conected in series with an individual group of lamps 97 in the minute lamp` bank 12. The SCR 96 and lamp group 97 are connected in series across the source of pulsating D.C. power 13. Within the diode matrix 19 each inputV 92 may be connected to more than one of the limiting resistors 95, to thereby select the groups o-flamps 97 required to indicate the desired numeral. The blocking diodes 94 prevent the actuation of lamps 97 through the plurality of input connections required where the individual lamp groups 97 are utilized in more than one numeral display. The diodes 93 also act as blocking diodes to prevent the tiow of current to the time ring counter 23 when the lamps 97 are being operated by the temperature controls.

The diode matrix 18 is similar to the matrix 19 and has a plurality of inputs 9S wired respectively to the outputs 9i) of the ring counter 22. Each of the inputs 98 is connected through a diode 99 to individual blocking diodes 160 wired to limiting resistance 1411 connected to the gate of a po'wer SCR 162. Each SCR 1112 is also connected in series across the source of power 13 along with a lamp group 103 in the ten-minute lamp bank 11. The operation of these components is analogous to those described with relation to the diode matrix 19.

The diode matrix 17 is similar to the matrixes 18 and 19. It comprises a plurality of inputs 104 wired respectively to the individual gate signal outputs 91 of the ring counter 21. Each input 104 is wired through a diode 105 and individual blocking diodes 106 to selected limiting resistances 107 connected to the gate of an individual power SCR 108. Each SCR 198 is connected in series with a lamp group 1129 across the source of DC. power 13. Thus it can be seen that the pulses received from the ring counters 21, 22 and 23 operate through the respective SCR switches 108, 192 and 96 to control the groups of lamps 199, I1113 and 97 which are activated to produce a desired time display.

Temperature controls The temperature display in this particular embodiment of the invention is derived from a servo mechanism device 29 shown in detail in FIGURES 6 9. A schematic representation of the temperature servo mechanism 20 is shown in FIGURE 5.

As shown by the schematic view in FIGURE 5, the temperature sensor 25 is wired to a D.C. bridge 110, which in turn is connected to servo ampliiier 111. The amplifier 111 controls a motor 112. The motor 112 operates a potentiometer 113 and is` connected to a unit switch generally designated by the numeral 114. The connection between the motor 112 and the unit switch 11e allows the motor shat to turn freely between units. There .is also a stepped connection from the shaft of motor 112 to a tens switch 115 which turns once for every ten steps turned by the units switch 114.

The gate signal lfrom line 39 is supplied to the rotor 116 of switch 115 at points 117 and 113. Switch 115 `is provided with a plurality of contacts 119 used to indicate tens units of temperature above zero and a plurality of terminals 129 used to indicate tens units of temperature below Zero. It the switch 11S is in any position representing a temperature above Zero, the gate signal from line 3S is passed to the point 117 through a strip 121 and line 122 to a tir-st point 123 on rotor 124 of the units switch 114. This causes the gate signal from line 38 to be passed to the outside contacts 125 of the unit switch 1141. At any position of switch representing a temperature below zero, the gate signal is routed by means of points 117, a second strip 126, and line 127, to a second point 123 on the rotor 124. Thus the gate signal will appear on the inside row of contact 129 of switch 114. The jumpers 139 connecting the outer terminals and the corresponding inner terminals 129 then reverse the indication supplied to the diode matrixes 17 and 18 so that the temperature indication will be correct at the lamp banks 10 and 11.

The terminals 125 and 129 are connected by outputs 131 to the temperature inputs 132 of the diode matrix 18 as shown in FIGURE 4. The inputs 132 are connected by diodes 133 to the individual blocking diodes 1119 to thereby select the particular SCRs 192 necessary to activate the lamps 193 for the unit display in the temperature indication. The .terminals 119 and 120 are wired by indiivdual outputs 1341 to the temperature inputs 135 of the diode matrix 17. Inputs 135 are connected by diodes 136 to the individual blocking diodes 196 to thereby select the SCRs 1118 necessary to activate the lamp groups 109 to thereby produce on the board the required lighted lamps to indicate the ten and hundred units of temperature. 1n addition, there is a direct contact from the strip 126 by means of line 137 which is wired directly to an SCR 133 controlling a special group of lamps 139 that shows a minus indication on the lamp bank 1@ when the temperature is below zero.

The temperature servo mechanism 2t) is more specifically seen in FIGURES 6-9. The unit is shown mounted on a plate 141i. The motor 112 drives a first gear 141 ymounted on the front of plate and meshing with a transfer gear 142. The transfer gear 142 in turn meshes with a first small gear 143 rotatably journalled on a shaft 144 supported by the plate 140. Gear 143 has an axiallyprotruding pin 1115 received within an arcuate slot 146 in a similar gear 147 iixed to the shaft 144. The shaft 144 is connected directly to the `rotor 124 of the switch 114 so that rotation of gear 147 will cause like rotation of the rotor 124. The length of slot 146 is such that the gear 1413 may turn an angular amount corresponding to the spacing of terminals 125 and 129 in the switch 114. Thus hunting of the motor 112 due to fractional temperature variations Will not be transmitted to the rotor 124.

Btl, which monitor existing light conditions.

Y 'il The gear 143 meshes directly with a large gear 1116 connected to the shaft of potentiometer 113, so that all motion transmitted from the motor 112 will be directly to-potentiometer 113 to provide the necessary balancing of the bridge 11i). The gear 1117 meshes with a second gear 149 mounted on plate 1451i. Gear 1119 has a pin 151i adapted to engage a slotted wheel 151 once for each revolution of 'the gear 149. The Wheel 151 is held in position by a yieldable stop 152. The wheel 151 is directly connected to the mounting shaft for the rotor 116 of switch 115. Thus, each time the switch 11d has been turned a full units, the switch 115 will be turned one unit to thereby step up the indication of the tens portion of the temperature digits.

Therc is also provided a holding circuit for motor 112 to insure lull movement of the rotor 12d between terminals 125 and 129. Mounted on the shaft 1de is an indexing wheel 153 slotted so as to correspond to the angular spacing of the terminals 125 and 129. The slots in the wheel 153 are adapted to be engaged by the hinged levers of small switches 1574 mounted onV a xed plate S. The individual switches 154 are connected to the power source for motor 112 so that one switch 154 will maintain the motor 112 in a iirst direction of motion when closed, and the other switch 15d `will maintain motor 112 in its second direction of rotation when i-t is closed. Gnly one of the switches 154i will close when the wheel 153 is turned in a given direction and that switch alone will cause the motor 112 to continue turning until the switch is opened by engagement oi the next slot in the wheel 153. Thus, each time the wheel 1.53 begins to turn, the respective switches 154 will insure the turning of shaft 14d to engage the successive terminals 125 and 129.

lt is also possible that the temperature responsive device could be electronically operated by means of ring counters or similar circuits. ln like manner the clock device of this mechanism can be controlled by a mechanical servomechanism such as that described with relation to the temperature device. ln either instance the two devices will control the SCR power circuits and the diode matrixes as described above. It also is to be understood that this application is not restricted to time and temperature indications but that the controlling devices may indicate any desired indicia, such as changeable highway speed, dates, scores', etc.

. Operation The operation of the controls described above should be evident from the descriptions previously given. Basically the large power loads are concentrated at the lamp banks 1li, 11 and 12 through the switching circuits 14, 15 and 16. The brightness controlling signal generator 29 and the counting circuits are operable on low circuits, so as to better utilize available semi-conductor elements.

All switching for the lamp banks 1li, 11 and 12 is carried out electronically at the SCRS 168, 102 and 96, which selec-t the lamp groups 1119, 103, 97 required for a desired display. Brightness of the lamps is automati cally controlled by the signal generator 29 and photo-cell By shifting the phase angle of the pulse at SCR 37, the signal generator controls the period of conduction at SCRs 1%, 102 and 96. The pulsating current at power supply 13 will cause the controlled lamps to be intermittently energized, and the length of the energized period will determine the lamp brightness. This feature is due to the characteristic of an SCR which allows it to continue to conduct current, after receiving a pulse, so long as current is applied across it. The pulsating current at power supply 13 then produces the necessary current gaps to permit control of lamp brightness.

The diode matrix arrangementl allows one to utilize the same electronic switching devices and brightness controis for display of a plurality of different quantities selected by independent controls. Although only two se- Q QJ lecting devices are shown above, any plural member may be utilized.

The electronic clock device is an improvement over mechanical devices in that it permits independent setting of minutes, ten minutes or hours, by use of reset switch 49 and switches 62, 63, d5, 6d, et? and 58. 1t is not necessary to run the unit through a display of several. hours to initially set it or for correction purposes.

rl`he temperature servo-mechanism 2@ is a simple device insuring proper temperature displays for rising'or falling temperatures. it automatically counts plus or minus degrees from zero, using a minimum of mechanical elements.

The controlling circuits as described above, will alternately display time and temperature on the lamp banks 1li, 11 and 1.2. No mechanical switching devices are utilized, thereby reducing maintenance. The use of modular semi-conductor circuits allows one to place the individual components on separate cards, which may be replaced or removed without disturbing the remaining portions oi the controls. The entire control unit may be very compact, and may be either mounted physically with the lamp banks 19, 11 and 12, or at a remote position.

Modied controls In FIGURE 13 is shown a modified circuit designed to replace the modular units shown in FIGURE 4; Although only a single lamp bank l@ is shown schematically in FlGURE 13, it is obvious that such an arrangement may be utilized in connection with each of the lamp banks. The lamp groups 16) are controlled di-l rectly by diodes 1,61 wired in a matrix leading to an individual SCR 162 for each digit to be displayed on the lamp groups loll. The gate power for the individual SCR 1M is supplied through blocking diodes 163 from a plurality of pulse sources generally designated as 164 and 165. The sources 164 and 165 may be inputs from the time and temperature mechanisms described above. The

individual SCR 162, the diodes 1&1 and the necessary lamp groups 161i are wired in series with a power suppl generally shown as 166.

This type of a circuit has the advantage of requiring fewer numbers of SCRs, however, it does necessitate the loading of the diodes 161 by the lamp supply 166. It is primarily advisable only where the lamps ldll'are operated at a low wattage. In addition the rectilers 162 might well be replaced by mechanical relays in conditions where maintenance is of no great significance.

Alternate lamp bank display Shown in FIGURES 10 through l2 is a lamp bank such as might be used on a highway as a changeable speed control indicator. The manner in which the indicated speed is arrived at isimrnaterial to the present disclosure and may be either automatic or manual in character. Basically the lamp bank is mounted on a stationary frame 17@ and has a hinged front panel 171 rotatably mounted by a hinge 172. The panel 171 may be a plastic panel and is preferably a sunscreen over the lamp cylinders 173.

The individual lamps of the bank are mounted in sockets 174 secured to the cylinders 173 at the back. endsV thereof. The lamp sockets 174 are wired to a diode matrix 175 which might be of the type shown in FIGURE 13, or of the type shown in FGURE 4. rIfhe diode matrix 175, which might also include suitable switches, relays, or SCRS, is wired to a controlling device adapted to select speeds to be indicated on the lighted lamps.

Quite obviously the controlling circuitry described above, might be utilized to display anyrequiredrdigits,

letters, or other information. The mechanisms removeV the necessity of mechanical parts and insure a long life of effective, changeable signs. Where necessary memory circuits may be included, so that in highway installations the speed indicated by the lamps would be repeateduntil changed, The display may even be continuous if so arrears-2 desired, being changed only periodically at weekly or monthly intervals. k

Various modifications will propose themselves to a person skilled in the art and for this reason the above examples are not intended to limit or restrict the invention except as it is delined in the-claims which follow.

Having thus described my invention, I claim:

1. A control apparatus for lamp bank displays cornprising: g k

a source of power;

a lamp `bank including a lplurality of lamps wired in lamp groups adapted to be selectively activated to` produce a desired lighted display;

gate controlled rectifier means, said lamp groups and said gate controlled rectifier means being wired in series across said source of power, said gate controlled rectifier means including gate connections for reception of an activated signal;-

gate signal generator means;

selector means operatively connected to thev gate connections of said gate controlled rectitiermeans and to said gate signal generator rneans'for completing selected connections between said gate signal generator means and said gate controlled rectitier means to `thereby establish desired connections across said power source through said .lamp groups and gate controlled rectifier means;

and a diode matrix comprising a plurality of parallel blocking diodes wired individually in series between said selector means and said lamp groups for preventing the completion of undesired circuits through lamp groups utilized in more than one of the desired .lighted displays.

. 2. A control apparatus for lamp bank displays, comprising: a source of pulsating direct current power;

a lamp bank including a plurality of individual'lamps wired in lamp groups adapted to be -.selectively activated to produce a desired lighted display; y

individual gate controlled rectifier means for cornpleting and holding a circuitatter reception of a gate signal, said lamp groups and-said gate conselected connections between said gate signal generator means andsaid gate controlled rectifier means to thereby establish desired connections across said power source through said lamp groups and gat controlled rectier means;

and a diode matrix comprising a plurality of parallel blocking diodes wired individually in series between said selector means and said lamp groups for preventing the completionof undesired circuits through lamp groups utilized inmore than one of the desired lighted displays.

3. A control apparatus as defined in claim 2 whereinsaid light controlled gate signal general means comprises:

an oscillator circuit operatively connected to said selector means;

and light responsive photocell means connected to (said oscillator circuit for varying'the phase angle of the oscillator signal responsive to the intensity of incident llight received thereby.

4. Acontrol apparatus as defined in claim 2 wherein said light controlled gate signal generator means compri es:

a second source of pulsating direct current;

second gate controlled rectifier'rneans lwired in series between said second source of pulsating direct cur- 'rent power and said selector means, said second gate controlled rectifier means'having a gate connection for reception of an activating signal;

an oscillator circuit wired' to the gate connection of said second gate controlled rectifier means;

.and light responsive photocell means connected to said oscillator circuit for varying the phase angle of the oscillator signal responsive to the intensity of incident light received thereby.

5. A control apparatus as defined in claim 2 wherein said selector means comprises:

an electronic counter'circuit for the counting of time in terms of minutes, tens of minutes and hours, said counter circuit including reset means torselectively advancing the counter circuit independently in each unit of time.

6. A control apparatus as defined in claim 2 wherein said selector means comprises:

a plurality of electrical circuits individually indicative of selected temperatures;

and temperature responsive servo-mechanism means operatively connected to said electrical circuits for selectively completing said electrical circuits.

7. A control apparatus as defined in claim 2 wherein said selector means comprises:

a temperature responsive circuit;

a time responsive circuit;

and means for selectively connecting said gate signal generator means to said temperature responsive circuit and said time responsive iny sequence. i

References Eited bythe Examiner UNrTED sTATEs PATENTS 11/31 Hull 315-157 2,123,459 7/38 Andersen 315-158 2,410,156 10/46 Flory 58-23 2,519,993 8/50 Allen 340-336 2,573,076 10/51 Welch 340-339 2,612,551 9/52 vlreiner' 340-176 2,918,608 12/59 Reith 340-336 2,920,240 1/60 Macnem 315-294 2,922,981 1/60 Anderson 340-336 2,953,776 9/60 Blutman 340-336 X 2,958,179 11/60 Wolfe et al 58-24 2,987,715 6/61 Jones et al S40-324.1 3,015,094 12/61 Reynolds 340-338 3,032,686 5/62 Mathis 340-336 3,041,596 6/62 Caferro et al 340-3091 FOREIGN PATENTS 237,893 9/ 60 Australia. 828,783 2/60-' Great Britain.` 1,210,415 3/60 France.

NE1L C. READ, Primary Examiner.

circuit in an alternat- 

1. A CONTROL APPARATUS FOR LAMP BANK DISPLAYS COMPRISING: A SOURCE OF POWER; A LAMP BANK INCLUDING A PLURALITY OF LAMPS WIRED IN LAMP GROUPS ADAPTED TO BE SELECTIVELY ACTIVATED TO PRODUCE A DESIRED LIGHTED DISPLAY; GATE CONTROLLED RECTIFIER MEANS, SAID LAMP GROUPS AND SAID GATE CONTROLLED RECTIFIER MEANS BEING WIRED IN SERIES ACROSS SAID SOURCE OF POWER, SAID GATE CONTROLLED RECTIFIER MEANS INCLUDING GATE CONNECTIONS FOR RECEPTION OF AN ACTIVATED SIGNAL; GATE SIGNAL GENERATOR MEANS; SELECTOR MEANS OPERATIVELY CONNECTED TO THE GATE CONNECTIONS OF SAID GATE CONTROLLED RECTIFIER MEANS AND TO SAID GATE SIGNAL GENERATOR MEANS FOR COMPLETING SELECTED CONNECTIONS BETWEEN SAID GATE SIGNAL GENERATOR MEANS AND SAID GATE CONTROLLED RECTIFIER MEANS TO THEREBY ESTABLISH DESIRED CONNECTIONS ACROSS SAID POWER SOURCE THROUGH SAID LAMP GROUPS AND GATE CONTROLLED RECTIFIER MEANS; AND A DIODE MATRIX COMPRISING A PLURALITY OF PARALLEL BLOCKING DIODES WIRED INDIVIDUALLY IN SERIES BETWEEN SAID SELECTOR MEANS AND SAID LAMP GROUPS FOR PREVENTING THE COMPLETION OF UNDESIRED CIRCUITS THROUGH LAMP GROUPS UTILIZED IN MORE THAN ONE OF THE DESIRED LIGHTED DISPLAYS. 